Low‐Valent Organobismuth Compounds with Intramolecular Coordination: cyclo ‐R 3 Bi 3 , cyclo ‐R 4 Bi 4 , RBi[W(CO) 5 ] 2 , and R 4 Bi 2 [R = 2‐(Me 2 NCH 2 )C 6 H 4 ]

The cyclobismuthanes R n Bi n , [R = 2‐(Me 2 NCH 2 )C 6 H 4 ; n = 3 ( 1a ), 4 ( 1b )] have been synthesised by reduction of RBiCl 2 with Na in liquid NH 3 or by reaction of R 2 BiCl with LiAlH 4 in Et 2 O. The reaction of 1a/b with W(CO) 5 ·THF afforded the bismuthinidene complex RBi[W(CO) 5 ] 2 ( 2 ). R 2 BiCl reacts with Mg in THF to give the dibismuthane R 4 Bi 2 ( 3 ). Single‐crystal X‐ray structure analyses of 1b , 2 , and 3 reveal intramolecular coordination of the pendant CH 2 NMe 2 groups to the bismuth atom. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)